bus

type Bus interface {
	// Subscribe registers a handler for a topic.
	// Returns a Subscription handle to cancel the registration.
	Subscribe(topic string, handler func(msg binary.Message)) Subscription

	// Publish sends a message to all subscribers of a topic.
	Publish(topic string, msg binary.Message) error

	// Topics returns a sorted list of all active topics.
	Topics() []string

	// Close shuts down the bus and clears all registrations.
	Close() error
}

type Subscription interface {
	Topic() string
	Cancel()
}